Prefix effect

Posted by: Adolfo Aguiar on 03 September 2001

I have in-board phono card in my NAC72 powered by Hi-Cap.
What sort of improvement should I expect with Prefix?
Would there be any improvement if Prefix was powered by a lesser PS (i.e. FlatCap 2) or is a Hi-Cap the minimum required?

Posted on: 03 September 2001 by Andrew L. Weekes

Adolfo,

The Prefix makes a big difference in my LP12, even when powered by the secondary output of my Flatcap2. It's a superb phono stage, and removing the arm cable seems to make a lot of difference.

I'm currently using a modified dual-railed, recapped SNAPS, which is even better, so improving the PSU makes quite a difference.

I'm certain the Prefix powered by a Flatcap2 will outperform the 72 / Hicap. Removing the phono boards from the 72 may have a subtle(?) effect too, reducing the load on the Hicap.

Andy.

Posted on: 04 September 2001 by NigelP

OK Andrew so now I'm really confused

I have a prefix powered by my 52 and an old Lingo with the filter mod (thanks for that one

). Now I see something else in the Earth loop discussions that I may be able to do more in the quest for excellence

. Do I need the Conn401/e or should I considered my safe from the evils of the Lingo? Please advise a very confused fellow. My lead from the Lingo is well away from everything else so I think that RF coupling can be ignored.

Regards,

Nigel

Posted on: 07 September 2001 by Adolfo Aguiar

I appreciate your contribution, which is very important to me to narrow my choices when I have the chance to visit a dealer in London.
Regards.

Posted on: 07 September 2001 by Andrew L. Weekes

quote:
OK Andrew so now I'm really confused I have a prefix powered by my 52 and an old Lingo with the filter mod (thanks for that one ).

You're welcome!

quote:
Now I see something else in the Earth loop discussions that I may be able to do more in the quest for excellence . Do I need the Conn401/e or should I considered my safe from the evils of the Lingo? Please advise a very confused fellow. My lead from the Lingo is well away from everything else so I think that RF coupling can be ignored.

From the perspective of audio, the Con401/E or it's absence makes no difference if you have a Prefix. The Conn401/E would just earth the chassis of the LP12, not make any connection to the earth lead that comes from the Prefix.

From a static drain point of view it could be useful if you're experiencing problems. I'm not, but I shall probably add a DIY conn 401/E to my LP12 anyway.

You do need a connection between mains and signal earth somewhere in the system. If you don't have a Naim CDP or any other source that makes this connection a wire from mains earth to the tag on the 52 would suffice.

Hope this makes sense.

Andy.

Posted on: 10 September 2001 by NigelP

Andrew,

Thank you for reassuring me. I have a CDS-II so signal to earth. I would be interested to know how you get on with the home-made lead though.

Regards,

Nigel